Bond alternation in the infinite polyene: effect of long range Coulomb interactions

Conference · Tue Jan 01 00:00:00 EST 1985

DOI:https://doi.org/10.1016/0379-6779(86)90066-4· OSTI ID:5692599

Mazumdar, S; Campbell, D K

We investigate the effects of long-range Coulomb interactions on bond and site dimerizations in a one-dimensional half-filled band. It is shown that the ground state broken symmetry is determined by two sharp inequalities involving the Coulomb parameters. Broken symmetry with periodicity 2k/sub F/ is guaranteed only if the first inequality (downward convexity of the intersite potential) is obeyed, while the second inequality gives the phase boundary between the bond-dimerized and site-dimerized phases. Application of these inequalities to the Pariser-Parr-Pople model for linear polyenes shows that the infinite polyene has enhanced bond alternation for both Ohno and Mataga-Nishimoto parametrizations of the intersite Coulomb terms. The possible role of distant neighbor interactions in photogeneration experiments is discussed. 26 refs., 3 figs.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5692599
• Report Number(s): LA-UR-85-2085; CONF-8504157-1; ON: DE85014109
• Resource Relation: Journal Volume: 13; Journal Issue: 1-3; Conference: Synthetic metals III workshop, Los Alamos, NM, USA, 9 Apr 1985
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
POLYACETYLENES
ELECTRONIC STRUCTURE
BAND THEORY
COULOMB SCATTERING
GROUND STATES
ONE-DIMENSIONAL CALCULATIONS
PHYSICAL RADIATION EFFECTS
THEORETICAL DATA
BASIC INTERACTIONS
DATA
ELASTIC SCATTERING
ELECTROMAGNETIC INTERACTIONS
ENERGY LEVELS
HYDROCARBONS
INFORMATION
INTERACTIONS
NUMERICAL DATA
ORGANIC COMPOUNDS
POLYENES
RADIATION EFFECTS
SCATTERING
360602* - Other Materials- Structure & Phase Studies